Following on from the first two volumes, published in 2002, volumes 3 and 4 of Characterisation and Engineering Properties of Natural Soils review laboratory testing, in-situ testing, and methods of characterising natural soil variability, illustrated by actual site data. Less well-documented soil types are highlighted and the various papers take into account location and distribution, engineering geology, composition, state and index properties, structure and engineering properties. Also treated is the quality and reliability of data with reference to methods of sampling and testing, and its relevance to engineering problems. These volumes will be useful to consulting engineers, geotechnical engineering academics and researchers, and civil engineers and soil scientists.